用户名: 密码: 验证码:    注册 | 忘记密码?
首页|听力资源|每日听力|网络电台|在线词典|听力论坛|下载频道|部落家园|在线背单词|双语阅读|在线听写|普特网校
您的位置:主页 > 每日焦点 > 文化娱乐 >

两天3颗小行星与地球“擦身而过”

2014-03-10    来源:新华网    【      美国外教 在线口语培训

3 small asteroids pass Earth closely but safely: NASA

An asteroid about 8 meters across passed Earth on Thursday at a relatively close but safe distance, the third such flyby in just two days, U.S. space agency NASA said.

The space rock, called asteroid 2014 EC, came within 62,000 kilometers of Earth's surface at about 4:21 p.m. EDT (2121 GMT), NASA said. That's just 16 percent of the distance between our planet and the moon, which is about 385,000 kilometers on average.

The asteroid, not visible to the unaided eye, was discovered Wednesday by the Catalina Sky Survey in Arizona.

"This is not an unusual event," said Paul Chodas, a senior scientist in the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory. "Objects of this size pass this close to the Earth several times every year."

The flyby of 2014 EC came closely on the heels of another two space rock encounters. On Wednesday afternoon, a 30-meter-wide asteroid, named 2014 DX110, zoomed by Earth, passing inside the orbit of the moon at a range of 350,000 kilometers.

A third asteroid, 2014 EF, which is closer in size to 2014 EC, passed Earth on Wednesday night, with closest approach about twice as far from Earth as 2014 EC's closest approach.

相关新闻:美国航天局6日说,一颗直径8米的小行星当天以非常近但比较安全的距离从地球近旁掠过,这也是两天来第3颗小行星与地球“擦身而过”。

这颗编号为2014 EC的小行星一天前才被发现,美国东部时间6日16时21分(北京时间7日5时21分)飞抵近地点,与地球的距离不到6.2万公里,只有地球与月球距离的大约六分之一。由于体积太小,不借助观测设备人们无法看到这颗小行星。

此前,一颗直径30米的小行星于美国东部时间5日下午(北京时间6日凌晨)从地球与月球之间穿过,与地球相距35万公里,约为地月距离的十分之九。美国东部时间5日晚(北京时间6日上午),类似的一颗小行星在距离地球约12万公里处掠过。

美国航天局近地天体项目高级科学家保罗·乔达斯说:“这不是非常罕见的情况,每年类似大小、类似距离小行星飞掠地球的事件会发生好几次。”(新华网)



顶一下
(0)
0%
踩一下
(0)
0%
手机上普特 m.putclub.com 手机上普特
[责任编辑:floater]
------分隔线----------------------------
发表评论 查看所有评论
请自觉遵守互联网政策法规,严禁发布色情、暴力、反动的言论。
评价:
表情:
用户名: 密码: 验证码:
  • 推荐文章
  • 资料下载
  • 讲座录音
普特英语手机网站
用手机浏览器输入m.putclub.com进入普特手机网站学习
查看更多手机学习APP>>